Device for Inserting Foundation Piles

ABSTRACT

A screwing device on a cantilever arm of a construction vehicle for screwing foundation installations into the ground has a suspension, a screw head, and an actuator. The actuator can be pivoted about two axes extending parallel to one another and transversely with respect to the longitudinal axis of the screw head. The articulation point on the screw head follows the motion of the pivoting lever on the longitudinal axis due to a migration of the articulation point from the longitudinal axis of the screw head occurring due to pivoting of the pivoting lever about the axes while screwing the foundation installation into the ground. The axes extend transverse to the longitudinal direction of the cantilever arm and are supplemented by at least one additional axis supported transversely with respect to said axes. This compensates for a migration of the articulation point in each direction.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is the U.S. National Stage of International Patent Application No. PCT/EP2012/064297, which has an international filing date of Jul. 20, 2012, and claims priority benefit of German patent application no. 10 2011 079749.1, filed Jul. 25, 2011. The entire contents of each of the foregoing are hereby incorporated herein by reference.

FIELD OF THE DISCLOSURE

The present disclosure relates to a screwing device for screwing foundation installations or the like into the ground as an attachment apparatus for attaching to the cantilever arm of a construction vehicle, as well as an excavator with such a screwing device.

BACKGROUND

Such screwing device are known per se. They exist as independent, for instance also self-propelled equipment with all necessary guides (gripping and aligning possibilities) and drives. As such they are appropriate and very comfortable, but comparatively complex. They are only profitable where a large number of foundation installations are to be used continuously.

For users with only occasional requirements such screwing devices actually only come into consideration as additional devices for attaching to the known multifunctional construction vehicle such as for example on the cantilever arm of an excavator into consideration. Only then are they financially viable for such users. One such additional device is described in U.S. Pat. No. 6,942,430 B1.

In the known apparatus, however, it is difficult to maintain the required screwing direction, whether it be perpendicular or another desired angle, actually over the entire drilling operation.

This is because the cantilever arm is lowered as the screwing operation proceeds. The articulation point of the tool on the cantilever arm follows a circular line around the pivot axis of the cantilever arm on the excavator. This means that, when no correction takes place, the drilling tool and with it the drill in its upper part follows the articulation point and is pushed in the longitudinal direction of the excavator arm out of the intended direction, so that the borehole can be changed in its direction or is extended to a possibly unwanted extent.

A similar alignment error is obtained in the case of lateral alignment, when the longitudinal axis of the screwing device is not aligned with the movement plane of the excavator arm, for instance because the excavator and with it the cantilever arm (in the case of a perpendicular screwing direction) are oriented obliquely or indeed the excavator is oriented upright but the screwing direction is different from the perpendicular. Superimpositions of this and the previously described sources of error can lead to erroneous deflections of the screwing device in every direction.

To these may be added further sources of error such as for example resistances in the ground which force the screwing device out of the intended alignment, and finally operating errors by the driver of the construction vehicle, such as may also occur in particular in the attempt to correct the previously described alignment errors.

In fact, according to the prior art the described misalignments are predominantly compensated for by means of the steering of the construction vehicle or of the cantilever arm, as depending upon the situation the vehicle driver drives the construction vehicle forwards or backwards or turns it or shortens, extends or pivots the cantilever arm.

However, this procedure itself conceals considerable inherent sources of errors, because the type and extent of the correction is dependent upon the judgment of the operator and upon the precision of his steering movements or also the technology (precision of the control). It is obvious that, above all in the case of driving movements on rough land and with devices designed for this operation this precision often leaves something to be desired.

A partial solution to these problems is offered by U.S. Pat. No. 3,746,104. There the cantilever arm of a drilling device can be adjusted in length hydraulically. As a result the directional corrections by driving the construction vehicle forwards and backwards are omitted, which are otherwise necessary, for example in order during lowering of the cantilever arm to prevent the migration of the articulation point out of the longitudinal axis the drilling device. The necessary correction takes place through the hydraulic alteration in length of the cantilever arm, instead of only through driving movements which are difficult to control precisely. However, this only solves the problem of the alignment errors in the longitudinal direction of the cantilever arm and even then does not solve it completely. When the cantilever arm assumes an angle other than a right angle to the direction of introduction of the drill, any alteration in length of the cantilever arm is at the same time associated with an alteration in terms of height. This leads—depending upon the direction of movement—to an unwanted tearing out or pressing in of the drill. In this solution other alignment errors must in any case be further compensated for by corresponding driving movements of the excavator, if need be by pivoting movements of the excavator assembly, with all the associated disadvantages, or it may not even be possible to compensate for them and they must be taken into account. Above all, however, this solution is also very complex, because it requires a cantilever arm which is completely different from the conventional one.

Another partial solution to the problem is disclosed by AT 387 424 B, in which the gimbal suspension of a drilling device is combined with hydraulic longitudinal adjustability thereof and so avoids movements of the cantilever arm and the problems associated therewith.

However, this subject matter also only avoids the problems resulting from movements of the cantilever arm. For other alignment errors which require readjustment of the device the document offers no solution. Here too the only options are the readjustment by means of driving movements of the construction device or adjusting movements of the cantilever arm or taking account of misalignments.

Furthermore this device is very complex and can hardly be considered above all for long foundation installations because it would require a height of the cantilever arm which is hardly available in the usual construction vehicles.

In order to solve these problems the applicant has proposed in DE 10 2008 022 478 a screwing device for foundation installations as an attachment apparatus which avoids or corrects alignment errors during screwing in a simple manner in that its articulation point on the cantilever arm is designed to be displaceable with respect to the screw head in at least a first direction transversely with respect to the longitudinal axis of the foundation installation, if appropriate also in a second direction transversely with respect to the first direction.

As a result the articulation point on the cantilever arm acquires the freedom to move, at least in the first direction, if appropriate also in the second direction and in this case in any direction due to the superimposition of the two movement options, away from the axis of the foundation installation without thereby acting laterally on the foundation installation and forcing it out of alignment.

Therefore the compensation here does not take place in the cantilever arm and not by alteration of the length thereof, but in the screwing device, more precisely at any location between the articulation point thereof on the cantilever arm and the screw head.

The error compensation here no longer necessitates conversion of the construction vehicle or its cantilever arm and also no longer has to take place by the highly inadequate means of steering of the construction vehicle. The compensation takes place in an additional part, which is in any case present, of the screwing device, namely its suspension. This reconfiguration is relatively compact, for example by comparison with the known hydraulic longitudinal adjustability of a drilling device. Above all, however, if the displacement is to take place in a driven and controlled manner, it can be carried out by (hydraulic) drives and controls thereof which are in any case provided in modern construction vehicles and are reserved for the additional equipment. Thus the displacement can be controlled manually by the operator in the simplest way.

As a particularly simple and structurally compact embodiment it is proposed in this connection to construct the suspension—as is known for drilling devices—as a universal joint and to lengthen one or both joint axes in such a way that they—and with them the articulation point and the screwing device—are displaceable with respect to one another.

This solution has proved successful in practice. However, a disadvantage of this solution is that it cannot be achieved with standard components—such as for instance with standard joints, in particular with standard universal joints—but the design requires appropriately shaped special joint parts which are moreover bulky and non-uniform, and accordingly heavy, complex in structure and therefore expensive and also require intensive maintenance and are prone to malfunction.

This gives rise to the object of implementing the decoupling of the screwing device from disruptive incorrect positions or incorrect movements of the construction vehicle or of the excavator in a simpler manner which is more cost-effective, less prone to malfunction and easier to maintain.

GENERAL DESCRIPTION

This object is achieved by the screwing device according to the present disclosure and an excavator with a corresponding screwing device.

This differs from the prior art in that the suspension, by means of which the screwing device can be articulated on the articulation point of the cantilever arm—optionally also by means of a conventional quick coupling—has an actuator which is designed as a pivot lever and can be pivoted at the end thereof nearest the screw head and at the end thereof nearest the cantilever—in the simplest case—about two first axes which extend parallel to one another and transversely with respect to the longitudinal axis of the screw head, in such a way that a migration of the articulation point at the cantilever end from the longitudinal axis of the screw head can be compensated for. That means that, due to the migration of the articulation point nearest the cantilever from the longitudinal axis of the screw head occurring due to pivoting of the pivoting lever about the axes while the foundation installation is being screwed into the ground, the articulation point nearest the screw head follows the motion of the pivoting lever on the longitudinal axis.

Since the main direction of the migration of the articulation point out of the longitudinal axis of the screw head is usually the longitudinal direction of the cantilever arm and therefore possibly in some cases actually only this deflection requires a correction, as a rule these first axes will be directed transversely with respect to the longitudinal direction of the cantilever arm in such a way that precisely this migration of the articulation point out of the longitudinal axis of the screw head in the longitudinal direction of the cantilever arm can be compensated for.

If it is desired to compensate for incorrect positions or incorrect movements of the articulation point also in another direction, for instance in the direction transversely with respect to the longitudinal direction of the cantilever arm, then this can be taken into account in that the actuator is designed to be pivotable on at least one of its ends additionally about a further axis extending transversely with respect to the longitudinal axis of the screw head and transversely with respect to the first axes.

If a complete decoupling of the screwing device from incorrect positions or incorrect movements of the articulation point is desired, then the actuator is designed to be pivotable on both its ends about two further axes extending parallel to one another, transversely with respect to the longitudinal axis of the screw head and transversely with respect to the first axes.

In this case there would have to be compensation for not only a migration of the articulation point out of the longitudinal axis of the screw head in the longitudinal direction of the cantilever arm and/or transversely with respect thereto. Instead, because of the possibility of superimposition of the two movement options any directional deviation should be compensated for.

In terms of design the simple solution would be that the one pair of axes provided on one end of the actuator or the pairs of axes provided on both ends of the actuator are constructed as universal joints.

This solution, which instead of a displaceability of the parts with respect to one another is based on a simple pivot lever construction, has considerable advantages over the prior art: It simplifies the compensation for possible directional errors with respect to the solution according to DE 10 2008 022 478 without giving up the advantages set out there. The design according to the present disclosure is of significantly simpler design than that of DE 10 2008 022 478. It operates with a simple actuator in the form of a pivot lever and simple joints, such as are commercially available as standard.

This applies in particular in so far as according to the present disclosure standard universal joints can be used which do not necessitate costly adaptation, not even any reconstruction, such as is necessary according to the embodiment according to the prior art. In addition, in these standard universal joints the susceptibility to malfunction and intensive maintenance requirements is significantly reduced relative to the special constructions according to the citation, which plays a particularly important part in rough operating conditions in earth works.

The actuator may have a rocker. This ensures particularly precisely guiding of the screwing device.

The pivoting of the actuator may take place manually. Preferably, however, at least one drive can be provided therefor.

This at least one drive can have a controlling/regulating arrangement by means of which the migration of the articulation point out of the longitudinal axis of the screw head can be detected and can be compensated for.

This can take place automatically by means of a control circuit which can be controlled mechanically or electrically.

For example, the actuator may have at least one tilt switch or a gyroscopic sensor from which the signals can be delivered to the drive by means of the controlling/regulating arrangement.

If the screwing device is also regarded as a device which is independent of the construction device, then this does not exclude the possibility that both have a common axis and this common axis at the same time forms the articulation point and one of the axes of the actuator.

If the device according to the present disclosure is also provided in principle as an attachment apparatus for construction vehicles which are designed for a change of attachment, then in the same way the use thereof as a fixed equipment attachment, for instance on an excavator only operated with this attachment, may be considered. Then it would be appropriate to connect the screwing device securely to the excavator, i.e. so as to be undetachable in operation, in such a way that they form a unit.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is described in detail below with reference to the drawings. In the drawings:

FIG. 1 shows an excavator 5 with cantilever 4 in three different working positions, such as occur during the screwing in of a screwed foundation 2;

FIG. 2 shows a screwing device according to the present disclosure;

FIG. 3 shows the device according to FIG. 2 in detail;

FIG. 4 shows a further embodiment of the device according to FIG. 2;

FIG. 5 shows a further detail of the device according to the present disclosure.

DETAILED DESCRIPTION

FIG. 1 shows, as an explanation of the problem which occurs with such devices, an excavator 5 with cantilever 4 in three different working positions such as occur during the screwing in of a screw foundation 2.

A straight line “A”, shown as a dash-dot line, indicates a desired screwing direction of a screw foundation 2 which during the screwing operation should be maintained in alignment with the longitudinal axis 12 of the screw head 8 and thus at the same time with the longitudinal axis of the foundation installation to be screwed in.

A circular line “B” indicates the line on which the articulation point 7 of the foundation installation 2 moves on the cantilever arm 4 during lowering of the cantilever 4 as the screwing operation proceeds, if this movement is not corrected. A sine curve “C” shows by way of example a sequence of movements for the articulation point 7 in the case where the operator attempts to prevent the migration of the articulation point 7 out of the line A by steering movements am excavator or by alteration in the length of the cantilever arm.

The illustration makes it clear that completely trouble-free screwing in of the foundation installation 2 whilst preventing erroneous deflections caused by lateral forces is not reliably possible. This is the starting point for the present disclosure, as FIG. 2 shows.

FIG. 2 shows a screwing device 1 according to the present disclosure with the foundation installation 2 attached to the screw head 8 thereof and already partially introduced into the ground 3. The suspension 6 of the screwing device 1 is articulated on the articulation point 7 of a cantilever arm 4. In this connection the suspension 6 has an actuator 9 constructed as a pivot lever which is articulated with its end 10 nearest the screw head on the screw head 8 and with its end 11 nearest the cantilever on the articulation point 7. Both articulations are disposed as axes 13 a and 13 b parallel to one another and transversely with respect to the longitudinal axis 12 of the screw head 8 in such a way that the actuator with its end 11 nearest the cantilever and the axis 13 a can follow the movement of the articulation point 7 on the circular line B which occurs during screwing, whilst with its end 10 nearest the screw head and the axis 13 b on its articulation point 20 nearest the screw head said actuator follows the movement of the screw head 8 on the straight line A or the longitudinal axis 12 of the screw head 8.

With this device it is possible to compensate for the migration of the articulation point 7 out of the longitudinal axis 12 of the screw head in one direction. Since the migration is primarily due to the lowering of the cantilever arm, it is normally this for which compensation is primarily required. The is achieved in that the pair of axes 13 a, b is oriented transversely with respect to the longitudinal direction 14 of the cantilever arm 4.

In order to compensate for incorrect positions of the cantilever arm 4 in the lateral direction (transversely with respect to the first direction, that is to say generally transversely with respect to the longitudinal direction 14 of the cantilever arm 4), the actuator 9 can be mounted at one of its ends, but optionally also at both of its ends, so as to be pivotable in each case about a further axis 15 a and 15 b extending transversely with respect to the longitudinal axis 12 of the screw head 8 and transversely with respect to the axles 13 a and 13 b and/or on the screw head 8.

If this is ensured—for example by a universal joint at each end of the actuator 9—it is possible to compensate for any relative movement between the articulation point 7 and the screw head 8 produced during screwing.

FIG. 3 shows a detail of the device according to the present disclosure as shown in FIG. 2. This shows the cantilever arm 4 with its articulation point 7, on which the actuator 9 is articulated as part of the suspension 6 with its end 11 nearest the cantilever with the axis 13 a. It also shows the articulation of the screw head 8 on the end 10 of the actuator 9 nearest the screw head with the axis 13 b. The further axis 15 b is also indicated.

Unlike in FIG. 2, in which the axles 13 a and b intersect the longitudinal axis 12 of the screw head 8, FIG. 3 shows a position of the device in which the articulation point 7 is located far outside the axis 12 of the screw head 8, whilst the articulation point 20 lies on the axis 12.

FIG. 4 shows a further embodiment of the device according to the present disclosure as shown in FIG. 2. This differs from the embodiment according to FIG. 2 in that here the articulation point 7 is indicated on a conventional quick coupling.

Moreover it is shown here, by way of indication, how an actuator configured as a rocker 16 brings about the compensation for the deviation between the articulation point 7 and the screw head 8 by means of a suitable drive 17 with control 18, for instance a tilt switch or gyroscopic sensor 19.

FIG. 5 shows in a further detail the articulation of the screw head 8 on the articulation point 20 on the end 10 of the actuator 9 nearest the screw head by means of axes 13 b and 15 b disposed at right angles with respect to one another. 

1. A screwing device for screwing foundation installations or the like into the ground as an attachment apparatus for attaching to a cantilever arm of a construction vehicle, said screwing device having a suspension, by means of which the screwing device can be articulated on an articulation point of the cantilever arm, and a screw head connected to the suspension, to which screw head the foundation installation to be screwed in can be coupled, and an actuator which is designed as a pivot lever, the actuator is articulated with its end nearest the cantilever on the articulation point of the cantilever arm and with its end nearest the screw head on an articulation point on the screw head and can be pivoted about parallel axes which extend through the articulation points and transversely with respect to the longitudinal axis of the screw head in such a way that, due to a migration of the articulation point from the longitudinal axis of the screw head occurring due to pivoting of the pivoting lever about the axes while the foundation installation is being screwed into the ground, the articulation point on the screw head follows the motion of the pivoting lever on the longitudinal axis.
 2. The screwing device according to claim 1, wherein the axes are directed transversely with respect to the longitudinal direction of the cantilever arm in such a way that it is possible to compensate for a migration of the articulation point out of the longitudinal axis of the screw head in the longitudinal direction of the cantilever arm.
 3. The screwing device according to claim 1, wherein the actuator is pivotable on at least one of its ends about a further axis extending transversely with respect to the longitudinal axis of the screw head and transversely with respect to the axes.
 4. The screwing device according to claim 1, wherein the actuator is pivotable on its ends about two further axes which are parallel to one another and extend transversely with respect to the longitudinal axis of the screw head and transversely with respect to the axes such a way that it is possible to compensate for a migration of the articulation point of the suspension out of the longitudinal axis of the screw head in any direction which occurs as the foundation installation is being screwed into the ground.
 5. The screwing device according to claim 3, wherein one or both of the pairs of axes is or are designed as universal joints.
 6. The screwing device according to claim 2, wherein the actuator has a rocker.
 7. The screwing device according to claim 1, wherein at least one drive is provided for the pivoting of the actuator.
 8. The screwing device according to claim 7, wherein the at least one drive has a controlling/regulating arrangement by means of which it is possible to compensate for the migration of the articulation point out of the longitudinal axis of the screw head.
 9. The screwing device according to claim 8, wherein the compensation takes place automatically by means of a control circuit which can be controlled mechanically or electrically.
 10. The screwing device according to claim 8, wherein the actuator has at least one tilt switch or a gyroscopic sensor from which the signals can be delivered to the drive by means of the controlling/regulating arrangement.
 11. An excavator with a screwing device according to claim 1, wherein the articulation point forms one of the axes of the actuator.
 12. The excavator according to claim 11, wherein the screwing device is connected securely and/or undetachably to the excavator.
 13. The screwing device according to claim 1, wherein the articulation point upon which the screwing device can be articulated is on a conventional quick coupling. 